Interest in the potential of OLED display technology has been driven by OLED display technology attributes that include demonstration of display panels that have highly saturated colors, are high-contrast, ultrathin, fast-responding, and energy efficient. Additionally, a variety of substrate materials, including flexible polymeric materials, can be used in the fabrication of OLED display technology. Though the demonstration of displays for small screen applications; primarily cell phones, has served to emphasize the potential of the technology, challenges remain in scaling the fabrication to larger formats. For example, fabrication of OLED displays on substrates larger than Gen 5.5 substrates, which have dimensions of about 130 cm×150 cm, have yet to be demonstrated.
An organic light-emitting diode (OLED) device may be manufactured by the printing of various organic thin films, as well as other materials on a substrate using an OLED printing system. Such organic materials can be susceptible to damage by oxidation and other chemical processes. Housing an OLED printing system in a fashion that can be scaled for various substrate sizes and can be done in an inert, substantially particle-free printing environment can present a variety of challenges. As the equipment for printing large-format panel substrate printing requires substantial space, maintaining a large facility under an inert atmosphere continuously requiring gas purification to remove reactive atmospheric species, such as water vapor and oxygen, as well as organic solvent vapors presents significant engineering challenges. For example, providing a large facility that is hermetically sealed can present engineering challenges. Additionally, various cabling, wiring and tubing feeding into and out of an OLED printing system for operating the printing system can present challenges for effectively bringing a gas enclosure into specification with respect to levels of atmospheric constituents, such as oxygen and water vapor, as they can create significant dead volume in which such reactive species can be occluded. Further, it is desirable for such a facility kept in an inert environment for processing to provide ready access for maintenance with minimum downtime. In addition to being substantially free of reactive species, a printing environment for OLED devices requires a substantially low particle environment. In that regard, providing and maintaining a substantially particle-free environment in an entire enclosed system provides additional challenges not presented by particle reduction for processes that can be done in atmospheric conditions, such as under open air, high flow laminar flow filtration hoods.
Accordingly, there exists a need for various embodiments of a gas enclosure that can house an OLED printing system, in an inert, substantially particle-free environment, and that can be readily scaled to provide for fabrication of OLED panels on a variety of substrates sizes and substrate materials, while also providing for ready access to an OLED printing system from the exterior during processing and ready access to the interior for maintenance with minimal downtime.